try to avoid segv

main.go

@@ -141,7 +141,7 @@ func getScsiBusSharingVMs(client *govmomi.Client) error {
 		// Determine cluster based on runtime host of VM based on https://github.com/vmware/govmomi/issues/1242#issuecomment-427671990
 		for _, host := range hsList {
 			if host.Reference() == *vm.Summary.Runtime.Host {
-				fmt.Printf("host %s matches with parent %s\n", host.Name, host.Parent)
+				fmt.Printf("host %s matches, host parent %s\n", host.Name, host.Parent)
 
 				var cluster mo.ManagedEntity
 				err = pc.RetrieveOne(ctx, *host.Parent, []string{"name"}, &cluster)
@@ -156,27 +156,33 @@ func getScsiBusSharingVMs(client *govmomi.Client) error {
 			}
 		}
 
-		if len(vm.Config.Hardware.Device) > 0 {
-			for _, device := range vm.Config.Hardware.Device {
-				//fmt.Printf("device: %v\n", device)
-				if scsi, ok := device.(types.BaseVirtualSCSIController); ok {
-					fmt.Printf("scsi: %v\n", scsi)
-					controller := scsi.GetVirtualSCSIController()
-					//fmt.Printf("controller: %s\n", device.GetVirtualDevice().DeviceInfo.GetDescription().Label)
-					fmt.Printf("VM %s is using SCSI bus sharing mode: %s\n", vm.Name, string(controller.SharedBus))
+		if vm.Config != nil && vm.Config.Hardware.Device != nil {
+			if len(vm.Config.Hardware.Device) > 0 {
+				for _, device := range vm.Config.Hardware.Device {
+					//fmt.Printf("device: %v\n", device)
+					if scsi, ok := device.(types.BaseVirtualSCSIController); ok {
+						fmt.Printf("scsi: %v\n", scsi)
+						controller := scsi.GetVirtualSCSIController()
+						//fmt.Printf("controller: %s\n", device.GetVirtualDevice().DeviceInfo.GetDescription().Label)
+						fmt.Printf("VM %s is using SCSI bus sharing mode: %s\n", vm.Name, string(controller.SharedBus))
+
+						if controller.SharedBus != "noSharing" {
+							result := BusSharingResults{
+								VmName:         vm.Name,
+								ClusterName:    clusterName,
+								ControllerName: device.GetVirtualDevice().DeviceInfo.GetDescription().Label,
+								SharingType:    sharedBusToString(controller.SharedBus),
+							}
+							busSharingResults = append(busSharingResults, result)
 
-					if controller.SharedBus != "noSharing" {
-						result := BusSharingResults{
-							VmName:         vm.Name,
-							ClusterName:    clusterName,
-							ControllerName: device.GetVirtualDevice().DeviceInfo.GetDescription().Label,
-							SharingType:    sharedBusToString(controller.SharedBus),
 						}
-						busSharingResults = append(busSharingResults, result)
-
 					}
 				}
 			}
+		} else if vm.Config == nil {
+			fmt.Printf("vm %s has no config\n", vm.Name)
+		} else if vm.Config.Hardware.Device == nil {
+			fmt.Printf("vm %s has no hardware device\n", vm.Name)
 		}
 
 	}
@@ -261,6 +267,10 @@ func main() {
 	//begin := flag.Duration("b", time.Hour, "Begin time") // default BeginTime is 1h ago
 	flag.Parse()
 
+	if len(*vURL) == 0 {
+		panic("Unable to connect to empty vCenter URL")
+	}
+
 	// Print logs to file
 	f, err := os.OpenFile("log.txt", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
 	if err != nil {